O.k. listen people...here is the true story. Sephiroth died in nibelheim...he was reicnarnated into a bird right, and then he pooped on midgar...The poop eventually got tracked onto the streets and hojo stepped in it...Then hojo went back to his lab and the poop got onto the floor, and jenova sucked up the poop and turned into sephiroth!

Jesus Christ you people read too deep into the game man.